One day a man forgot how to walk downstairs.
He simply couldn't remember which foot came first, the left or the right.
Seeing no easy solution to the problem he decided to spend the rest of his life upstairs.
He managed to survive a few days on some mints he'd found in the bedside drawer and water from the bathroom hot water tap.
After that he ate the loft insulation.
And then his work shirts.
At the start of the second week he grew desperate and thought of shouting for help from the window. But he was likely to attract the attention of Nigel, his nosy next door neighbour who would never let him live down the embarrassment.
At the start of the third month the water was cut off. He worked his way around this problem by placing his work ties on a stick outside the window. He would wait until it rained and then wring them into his mouth.
By the sixth month he'd started eating the wallpaper in the guest bedroom.
On the anniversary of his life upstairs he celebrated with a fly he'd found on the windowsill which he'd been saving for a special occasion.
Around this time a small crowd had gathered below his window, likely attracted by the strange sight of a heavily bearded man waving a variety of tattered ties from a stick. They'd became apprised of the situation.
'I've never heard of anything so ridiculous' someone in the crowd said. 'Everyone knows it's the right foot that comes first.'
'What? I'm surprised you've got as far in life as you have thinking that, everyone knows it's the left!'
An argument broke out amongst the crowd, which had split into two distinct factions, the lefts and the rights and a minor third faction which suggested you could get down stairs by using both feet simultaneously. The conflict escalated and eventually had to be broken up by the army.
On the silver anniversary of his life upstairs, he died.
He was found several years later.
A statue was erected in his honour, depicting a man at the top of a flight of stairs gazing down indecisively at his feet.
The authorities launched a nationwide campaign warning its citizens of the dangers of living solely upstairs and that it was definitely the left foot that came first.
Although others, many leading scientists and philosophers among them, still insisted that it was the right.